Isolation, structural studies and chemical synthesis of a 'palmitone lipid' from Corynebacterium diphtheriae

The isolation of a 'palmitone lipid' from Corynebacterium diphtheriae is described. The use of a temporary hydrophobic protecting group allows the obtaining of the lipid in free and pure form. Structural studies by chemical degradation and mass spectrometry allow one to propose structure Ic for this compound, namely 6-(2-tetradecyl 3-keto octadecanoyl)-alpha-D-trehalose. This structure was confirmed by chemical synthesis.